sedimentary

Bivalve Fossil (Clam/Mollusk)

Class: Bivalvia (Order: Veneroida), Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 (Mohs scale), Color: Cream/Tan to Dull White, Luster: Dull/Earthy (can be pearly if aragonite is preserved), Structure: Ribbed concentric growth lines, Cleavage: None (conchoidal fracture on shell material), Specific Gravity: 2.7

Identified March 15, 2026More sedimentary →

Explore Bivalve Fossil (Clam/Mollusk) in the encyclopedia →

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Physical properties

Formation & geological history

Formed by biological precipitation of calcium carbonate in marine or freshwater environments. Petrified through permineralization or replacement within sedimentary layers. Geologically ranging from the Cambrian period to the Holocene.

Uses & applications

Paleontological study, educational tools, local craft jewelry, and inexpensive fossil collecting.

Geological facts

Bivalves are one of the most common fossils found worldwide. They have two hinged shells (valves) and have survived through several mass extinction events, making them excellent indicators for dating the age of sedimentary rock layers.

Field identification & locations

Identify by looking for symmetrical 'D' or kidney-shaped outlines with visible concentric growth ridges. Commonly found in limestone, shale, and sandstone outcrops near former sea beds or riverbanks.